Modulating makeup fluid control systems and methods for same

ABSTRACT

A method for maintaining a boiling rate of a base fluid can include a determination of a fluid level of a turbulated base fluid in a reservoir. The fluid level can be determined by measuring at least one first height of the turbulated base fluid above the fluid level with at least a first sensor. The fluid level can be determined by measuring at least one second height of the turbulated base fluid below the fluid level with the first sensor. The method can include the establishment of the fluid level of the turbulated base fluid. The fluid level can be established according to the measured at least one first and second heights. The method can include the graduated introduction of an input fluid into the reservoir. A control valve can gradually introduce the input fluid in proportion to the established fluid level of the turbulated base fluid.

CLAIM OF PRIORITY

This patent application claims the benefit of priority of Abel U.S.Provisional Patent Application Ser. No. 62/439,686 entitled “MODULATINGMAKEUP FLUID CONTROL,” filed on Dec. 28, 2016 (Attorney Docket No.4659.001PRV) which is hereby incorporated by reference herein in itsentirety.

BACKGROUND

A building (e.g., residence, multi-family dwelling, office building,municipal building or the like) will often include heating, ventilating,and air conditioning (“HVAC”) appliances to control the atmosphere(e.g., temperature) within the building. In some examples, a humidifieris included with the HVAC appliances to control the amount of humiditypresent in the atmosphere within the building. An example humidifierincludes a tank, a heat source, and a valve for introducing water intothe tank. As the heat source heats—and ultimately boils—the water insideof the tank, steam escapes the tank through a steam discharge.

In order to maintain a proper water level within the tank, additionalwater is added to the tank as steam escapes the tank. Water is added toreplace the water that was converted to steam and to ensure continuedoperation of the humidifier. In some examples, a float valve is used tocontrol the introduction of water into the tank. In another example, awater level sensor is installed within the tank and is configured tosense when the water level rises above the sensor. A controller is incommunication with a valve and the water level sensor is used tointroduce water into the tank when the water level within the tankreaches a predetermined level (e.g., the water level falls below thewater level sensor).

SUMMARY

A problem to be solved includes a diminished boiling rate of a fluidwithin a reservoir when additional fluid is introduced into thereservoir. In an example where the fluid is water and the reservoir is atank for a humidifier, a diminished boiling rate of the water within thetank causes a decrease of production of steam within the humidifiertank. In an example where the humidifier discharges steam into anenvironment (e.g., a room, a building, or the like), a decrease inproduction of steam within a humidifier tank causes unacceptablevariations of humidity within the environment. In some examples, systemsfail to maintain the boiling rate of a fluid within a reservoir becausethe systems lack the capability to precisely measure the fluid level ofa turbulated base fluid within the reservoir and gradually introducemore fluid into the reservoir. Existing systems introduce water in animprecise manner such that the boiling rate of the fluid within thereservoir diminishes to an unacceptable rate.

The aforementioned problems are solved with a system and method formaintaining a boiling rate of a base fluid. A fluid level (e.g., anactual fluid level) of a turbulated base fluid is determined in areservoir by measuring at least one first height and at least one secondheight of the turbulated base fluid above and below a first sensor,respectively. In an example, the first height is above the fluid leveland the second height is below the fluid level. The fluid level of theturbulated base fluid is established according to the measured at leastone first and second heights. Establishing the fluid level with the atleast one first height and at least one second height improves theaccuracy of the determination of the water level. Additionally,measuring in this manner more precisely determines the fluid levelbecause the fluid level is determined within a range of levels asopposed to existing systems that determine the fluid level at discretepoints. Stated another way, measuring in this manner allows for greaterresolution of fluid levels as compared to existing systems. Further,measuring in this manner improves the accuracy and precision of waterlevel determinations as compared to a floating level sensor because thefloating level sensor, in operation, provides an inconsistent waterlevel because the base fluid is moving (e.g., turbulated).

Additionally, the method also includes, in at least some examples,graduating the introduction of an input fluid into the reservoir with acontrol valve. The control valve introduces the input fluid in agraduated manner in proportion to the consistently accurate and reliablyestablished fluid level of the turbulated base fluid. Graduating theintroduction of an input fluid into the reservoir based on the accurateand high resolution determination of the liquid level maintains theboiling rate of a base fluid because the input fluid is added in amoderated manner, instead of being introduced in large quantities when afloat or level sensor is triggered. The boiling rate is maintainedbecause the input fluid, at a temperature below the boiling temperatureof the base fluid, is introduced in a measured manner that does notdecrease the temperature of the base fluid below the boiling temperatureof the base fluid.

This overview is intended to provide an overview of subject matter ofthe present patent application. It is not intended to provide anexclusive or exhaustive explanation of the invention. The detaileddescription is included to provide further information about the presentpatent application.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numeralsmay describe similar components in different views. Like numerals havingdifferent letter suffixes may represent different instances of similarcomponents. The drawings illustrate generally, by way of example, butnot by way of limitation, various embodiments discussed in the presentdocument.

FIG. 1 is a cross sectional view of one example of a system forproducing vapor.

FIG. 2 is a side view of one example of a sensor array.

FIG. 3 is a side view of the sensor array of FIG. 2 and a turbulatedbase fluid.

FIG. 4 is a schematic view showing one example of a fluid levelmeasuring apparatus.

FIG. 5 is a block diagram showing one example of a method formaintaining a boiling rate of a base fluid.

DETAILED DESCRIPTION

FIG. 1 is a cross sectional view of one example of a system 100 forproducing vapor. In some examples, the system 100 includes a humidifier,a boiler, or the like. The system 100 shown in FIG. 1 includes a tank110 defining a reservoir 115. The reservoir 115 is configured to containa base fluid. In one example, the base fluid includes water (e.g., tapwater, deionized water, distilled water, or the like). In someinstances, the base fluid is turbulated inside the reservoir 115. In anexample, the turbulated base fluid is a fluid having a turbulent,agitated or undulating surface. As described herein, the base fluid isoptionally driven my mechanical, fluid or thermodynamic mechanisms intothe turbulated configuration. Optionally, the base fluid is turbulatedwith one or more fluid or thermodynamic processes that precipitateboiling including, but not limited to, heating of the fluid such aswater, decreasing ambient pressure in the reservoir to trigger boilingor the like.

Referring again to FIG. 1, in one example, the system 100 includes oneor more heaters 130 (e.g., resistive heating elements, boiler tubes orthe like). The one or more heaters 130 are configured to supply thermalenergy to the base fluid contained within the reservoir 115. In someexamples, the system 100 includes a heat exchanger configured to supplythermal energy to the base fluid contained within the reservoir 115. Forinstance, in one example, the heat exchanger is positioned in thereservoir 115 and is in communication with the base fluid containedwithin the reservoir 115. Additionally, the heat exchanger is incommunication with a heat source (e.g., a boiler, natural gas burner,geo-thermal source, or the like) that supplies thermal energy to a fluidthat flows through the heat exchanger, thereby heating the base fluidcontained within the reservoir 115. The one or more heaters 130, heatexchanger or the like are optionally configured to turbulate the basefluid through initiation and maintenance of boiling.

In some instances, the system 100 includes a cover 140 coupled with thetank 110. The system 100 includes a discharge 145 in communication withthe reservoir 115. In some examples, the cover 140 includes thedischarge 145 communication with the reservoir 115. The discharge 145 isthe outlet for the base fluid from the reservoir 115. As describedherein, in an example the turbulated base fluid is boiling water. Theboiling water in the reservoir 115 produces steam and the steam flowsfrom the reservoir 115 through the discharge 145. Optionally, thereservoir 115 is sealed (with the exception of the discharge 145) toprevent the base fluid from otherwise escaping from the reservoir 115.Further, sealing the reservoir 115 facilitates the maintenance ofspecified pressures, temperatures and the like.

The system 100 includes one or more sensors. In an example, the one ormore sensors are included in a sensor array 120. As shown in the exampleprovided in FIG. 1 the sensor array 120 includes a first sensor 121 anda second sensor 122. In some instances, the sensor array 120 includesone or more sensors (e.g., one, two, or three or more sensors). Asdiscussed herein, the one or more sensors are configured to monitor abase fluid level (e.g., an actual amount, the volume of, the quantityof, or the like) in the reservoir 115.

In another example, the system 100 includes a control valve 150, such asa modulating control valve. The modulating control valve 150 introduces(e.g., permits flow, inputs, directs, deposits, provides, or the like)an input fluid, such as water, into the reservoir 115. The modulatingcontrol valve 150 is in communication with an input fluid source (e.g.,municipal water system, deionized water source, or the like). In someexamples, the modulating control valve 150 is configured to provide avariety of orifice sizes, opening sizes or the like to control a flowrate of the input fluid into the reservoir 115. For instance, themodulating control valve provides one or more flow rates of the inputfluid, including a range of flow rates, to the reservoir 115 based on aspecified flow rate (e.g., determined with the sensor array 120, asdescribed herein).

In some examples, the system 100 includes an overflow 160. The overflow160 includes an opening in communication with the reservoir 115. Theoverflow 160 is configured to prevent the base fluid level within thereservoir 115 from exceeding a specified level, thereby preventing thereservoir 115 from overfilling with the base fluid. In another example,the system 100 includes a drain 170 configured to substantially emptythe reservoir 115 of the base fluid (e.g., for maintenance, transport orthe like).

FIG. 2 is a side view of one example of a sensor array 120. As discussedherein, the one or more sensors are configured to monitor the base fluidlevel in the reservoir 115 (shown in FIG. 1). In some examples, the oneor more sensors include on/off float switches configured to monitor thebase fluid level in the reservoir 115 (shown in FIG. 1). In someinstances, the one or more sensors include electrical characteristicinstruments, such as an impedance sensor. In an example, the electricalcharacteristic instruments measure the impedance (e.g., resistance,conductivity, capacitance, inductance or the like) of the base fluid tomonitor the base fluid level in the reservoir 115. In one example, theimpedance sensor measures the capacitance or inductance of deionizedwater to monitor the base fluid level in the reservoir 115.

In another example, the one or more sensors includes a conductance probe200. In the examples shown in FIGS. 1, 2, and 3; a plurality ofconductance probes are used. In an example, the conductance probe 200 issheathed in an electrically insulative material and a tip of theconductance probe 200 is exposed (e.g., sheathing is removed). Theexposed tip of the probe 200 provides one or more of the first or secondsensors 121, 122. In an example, the first sensor 121 is incommunication with base fluid, such as water, contained in the reservoir115. An electrical signal is transmitted to the first sensor 121. Thewater contains impurities that allow the electrical signal to betransmitted from the first sensor 121, through the water, and to thetank 110 (shown in FIG. 1). In some examples, the electrical signal isused, such as by determining the resistance between the first sensor 121and the tank 110 (shown in FIG. 1), to determine (e.g., monitor) thatthe water level within the reservoir 115 is at a specified level (e.g.,low level, normal operating level or a full level).

In an example, the system 100 (shown in FIG. 1) uses existing componentsin a discrete fluid level control system including one or more sensorsconfigured to detect a turbulated base fluid at one or more levels(e.g., heights, depths or the like) in the reservoir. In some examples,a fluid level sensor (e.g., the first sensor 121 or the second sensor122) determines that the fluid level is at or above a particular heightcorresponding to the position of the sensor element. Stated another way,a fluid level sensor detects the fluid at two positions: at or above thefluid level sensor (e.g., in communication with the sensor), and belowthe fluid level sensor (e.g., not in communication with the sensor).

In some examples, the reservoir is a humidifier water tank. Boiling of afluid (e.g., used to generate vapor for introduction to a stream of gas)creates turbulence in the fluid (e.g., waves, ripples, bubbles, or thelike). With turbulence in the fluid, other devices used to measurediscrete fluid levels sense periodic on and off conditions thatfrustrate the accurate measurement of the fluid level. In some examples,the turbulence in the base fluid is created by a mechanical device(e.g., a paddle, a pump, a oscillating or reciprocating mechanism, orthe like) alone or in combination with a thermodynamic basedturbulation, such as boiling. In an example where the turbulent state ofthe base fluid (e.g., water) results in a series of undulations (e.g.,waves, bubbling surface or the like) on the surface of the base fluid,the height of the undulations vary depending on one or more of theboiling rate, mechanical turbulation or the like of the base fluid.

In the example of the discrete fluid level control systems describedherein, turbulation of the fluid is used advantageously to accuratelyand precisely establish the fluid level (e.g., quantity, height, volumeor the like) under dynamic conditions including evaporation, in flow,out flow, turbulation, boiling, or the like. More accurate and precisedetermination of the fluid level is achieved by sensing the fluid levelover a period of time and under dynamic conditions. Stated another way,the fluid level of the turbulated base fluid is established according tothe measured at least one first and second levels sensed by the fluidlevel sensor (e.g., the first sensor 121).

Referring again to FIG. 2, in an example where the sensor array 120includes the first sensor 121 and the second sensor 122. The firstsensor 121 is located at a first sensor location, such as a firstelevation. The second sensor 122 is located at a second sensor location,such as a second (higher) elevation. In an example, the second sensorlocation is different from the first sensor location. For instance, thefirst sensor 121 differs in length with respect to the second sensor122. The fluid level sensor array 120 discerns that the base fluid levelis in one of three regions (e.g., at one or more levels, heights, depthsor the like). In the example provided below, the three regions include(but are not limited to) a first region 210, a second region 220, and athird region 230. In the first region 210 none of the probes (e.g.,including the lowest elevation first sensor 121) sense the base fluid(e.g., water). In some examples, the first region 210 is assigned anumerical value of 0 for fluid level indexing purposes. The secondregion 220 corresponds to one probe (e.g., the first sensor 121)detecting the base fluid. In some examples, the second region 220 isassigned a numerical value of 1 for fluid level indexing. The thirdregion 230 corresponds to two probes (e.g., the first sensor 121 and thesecond sensor 122) detecting the base fluid. In some examples, the thirdregion 230 is assigned a numerical value of 2 for fluid indexingpurposes.

As described herein, in an example, the base fluid in the reservoir 115(shown in FIG. 1) is turbulated. The level of the turbulated base fluidis measured to determine if additional fluid (e.g, the input fluiddescribed with reference to FIG. 1) is specified for input to thereservoir 115. In some instances, measuring the level of the turbulatedbase fluid includes measuring a first level and a second level of theturbulated base fluid (e.g., a peak and trough of the turbulated fluid).In an example, measuring the first height and the second height of theturbulated base fluid includes sensing the turbulated base fluid is inthe first region 210 (e.g., below the first sensor 121). In anotherexample, measuring the first height and the second height of theturbulated base fluid includes sensing the turbulated base fluid is inthe second region 220 (e.g., between the first sensor 121 and the secondsensor 122, or above the first sensor 121 and below the second sensor122). In yet another example, measuring the first height and the secondheight of the turbulated base fluid includes sensing the turbulated basefluid is in the third region 230 (e.g., at or above the second sensor122).

FIG. 3 is a side view of the sensor array 120 of FIG. 2 and a turbulatedbase fluid 300. An undulation of the turbulated base fluid has a wavemidpoint 330 (e.g., a wave centerline) between the peak 320 and trough310 of the wave. In some instances, the wave midpoint 330 corresponds tothe base fluid level within the reservoir 115. In an example where thewave midpoint 330 is located at the lower probe (e.g., the first sensor110), the fluid level is determined by detecting the turbulated basefluid at one or more heights in the reservoir 115 (shown in FIG. 1)several times per second over the course of a time period (e.g., asampling period, duty cycle or the like such as every 5, 10, 15, 20seconds, a minute or the like).

As described herein, in some instances, the first region 210 (shown inFIG. 2) is assigned a numerical value of 0 for fluid level indexing.Similarly, the second region 220 and the third region 230 are assigned anumerical value of 1 and 2, respectively. With the wave midpoint 330coincident with the first sensor 110, the numerical values generatedfrom the first sensor 110 result in a roughly 50:50 ratio of sensing anumerical value of “1” (e.g., the first height) and sensing a numericalvalue of “0” (e.g., the second height). The average of those readings isapproximately “0.5”. In another example, if the wave midpoint 330 heightis not at the height of the first sensor 110 (is above or even below thefirst sensor 121 because of contact by the wave crests) the numericalvalues range from 0 to 1 with a corresponding varying ratio. In yetanother example, if the wave midpoint 330 height is proximate the heightof the second sensor 120, the numerical values range from 0-2 (or 1-2depending on the amplitude of the undulations) because at least the peakof the base fluid contacts the second sensor 120.

In an example, the quantity of numerical values are equal to the numberof readings that were taken in a sample period. For instance, if 20samples are measured over a sample period of one second, data generated(numerical values as described above) are in increments of 1/20 secondsor 0.05 seconds. By increasing the sampling rate of the fluid sensor,the system 100 provides greater resolution and corresponding higherprecision and accuracy of the fluid level determination.

As described herein, in some examples, the first height and the secondheight of the turbulated base fluid is measured by the sensor array 120.In an example, measuring the first height or the second height of theturbulated base fluid includes measuring a first time period theturbulated base fluid is above the first sensor 121 during a sampleperiod. Additionally, measuring the first height or the second height ofthe turbulated base fluid also includes measuring a second time periodthe turbulated base fluid is below the second sensor 121 during thesample period. Further, measuring the first height or the second heightof the turbulated base fluid also includes establishing one or more ofthe first height or the second height according to the measured firsttime period and second time period. In this example, the measuring ofthe first height or the second height is accomplished similarly to theaforementioned examples. However, in addition to establishing whether ornot the fluid is in a region (e.g., the first region 210, the secondregion 220, or the third region 230), the apparatus evaluates the lengthof time that the fluid is within a particular region. Stated anotherway, the apparatus establishes the fluid level of a turbulated basefluid by determining the length of time the turbulated base fluid issensed (and not sensed) by a fluid level sensor (e.g., the first sensor121).

In contrast to a system that measures discrete values (e.g., 0, 1, 2, orthe like) with an ordinary sampling scheme, the system 100 is able tomeasure more precise and accurate values (e.g., 0.05, 0.45, 1.35, or thelike). For example, if 100 readings were conducted over a sample periodand 35 of those readings produced a numerical value of 2, and 65 ofthose readings produced a numerical value of 1, the average value ofthose readings is 1.35. In other words, the wave midpoint 330 of theturbulated base fluid is 35 percent between the first sensor 110 and thesecond sensor 120. In an example, the first sensor 110 is spaced teninches from a bottom of the tank 110 (shown in FIG. 1). The secondsensor 120 is spaced from the first sensor 110 by one inch (e.g., thesecond sensor is eleven inches from the bottom of the tank 110). Thereading of 1.35 signifies that the wave midpoint 330 is located at 10.35inches from the bottom of the tank 110.

The ability of the system 10 to measure more precise and accurate valuescontrasts with a discrete system that is only capable of sensing waterat specific levels and performing operations as a result. For example, adiscrete system will sense that the second sensor 122 is not incommunication with a base fluid. In response, the system will operate afill valve (e.g., the control valve 150 shown in FIG. 1) until the basefluid is in communication with the second sensor 122. Once the basefluid is in communication with the second sensor 122, the system willcease operation of the fill valve (e.g., stop the introduction of thebase fluid into the reservoir 115). The present subject matter iscapable of establishing that the fluid level is at a non-discrete value(e.g., 1.35) and then metering the introduction of an input fluid suchthat the fluid level rises to the specified level (e.g., a numericalvalue of 2, or coincident with the second sensor 120).

Other operations are possible to be performed on the range of numericalvalues collected during the sample period. For example, the numericalvalues are inputs into a mathematical model that determines the fluidlevel. In other examples, the numerical values are inputs intoproportion, integration, or derivative (“PID”) loop (or a combinationthereof). The PID loop periodically determines an error value that isthe difference between a process set point (e.g., the desired humidityin an environment or desired fluid level within a reservoir) and aprocess variable (e.g., the actual humidity in an environment or actualfluid level within a reservoir). The PID loop parameters are optimizedto best minimize the error value. The resultant value computed by thePID loop is used to adjust a control variable. In one example, thecontrol variable is an input signal into a control valve. In someexamples, and as will be discussed further herein, the range ofnumerical values collected during the sample period are used to create aturbulent surface parameter.

As described herein, in some examples, the first height and the secondheight of the turbulated base fluid is measured by the sensor array 120.In yet another example, the measuring of the first height or the secondheight is established according to a proportion of the measured firsttime period to the second time period. Stated another way, the first orsecond height of the turbulated base fluid is determined by evaluatingthe amount of time that the fluid is within a particular region incomparison to the time that the fluid is within another region. Theresult of the comparison establishes the fluid level within thereservoir 115 (shown in FIG. 1). For example, and as shown in FIG. 3,the first sensor 121 dynamically and automatically measures the heightof the fluid level based on the wave form of the turbulated base fluid.In this example, the first sensor 121 detects the fluid (e.g., the waveis at or above the first sensor 121) around 50 percent of the period(e.g., of the wave, time interval, or the like) and accordingly does notdetect the fluid the remaining 50 percent of the period (the fluid isbelow the sensor element). Based on the 50/50 proportion of the sensedheights and the location of the sensor element the system determines thefluid level (in this example) is accurately and precisely located at thefluid level shown in dashed lines. In other examples where theproportion changes (e.g., 70 at or above and 30 below) fluid level isestablished at a corresponding proportional location above the firstsensor. In still yet another example, the aforementioned examples formeasuring the first or second height are performed repeatedly on anongoing basis, and the output (determined height) is automaticallyupdated based on the continued measurements.

FIG. 4 is a schematic view showing one example of a fluid levelmeasuring apparatus 400. In describing the fluid level measuringapparatus 400, reference is made to one or more components, features,functions and operations previously described herein. Where convenient,reference is made to the components, features, operations and the likewith reference numerals. The reference numerals provided are exemplaryand are not exclusive. For instance, components, features, functions,operations and the like described with respect to the fluid levelmeasuring apparatus 400 include, but are not limited to, thecorresponding numbered elements provided herein and other correspondingelements described herein (both numbered and unnumbered) as well astheir equivalents.

In some examples, the fluid level measuring apparatus 400 includes amakeup controller 410. In one example, the makeup controller 410includes a sampling module 420. In some instances, the sampling module420 is in electrical communication with the fluid level sensor array 120and is configured to receive one or more measurements (e.g., values) ofthe fluid level from the fluid level sensor array 120. In anotherexample, the makeup controller 410 includes a fluid level identificationmodule 430. In some instances, the fluid level identification module 430is configured to determine a turbulent fluid surface parameter, based onthe one or more measurements of the fluid level (e.g., within thereservoir 115 shown in FIG. 1). In yet another example, the turbulentfluid surface parameter corresponds to the amount of the base fluid(e.g., volume) contained in the reservoir 115.

Referring again to FIG. 4, in an example, the range of values (e.g., ofthe turbulent surface parameter) is used as an input to the makeupcontroller 410 in a manner similar to the use of an analog temperaturemeasurement that is used to control a modulated heating process. In oneexample, the apparatus 400 includes the control valve 150. The controlvalve 150 is coupled to the reservoir 115 (shown in FIG. 1) for themetered (e.g., graduated) introduction of an input fluid (e.g., water)into the reservoir 115. In another example, the control valve 150 has avalve opening 440, wherein the valve opening is configured to be openedand closed. In yet another example, the valve opening 440 is configuredto regulate flow through the control valve 150 between flow ratesincluding no flow, full flow and one or more moderated flow ratestherebetween. In still yet another example, the control valve 150 isconfigured to control a flow rate of an input fluid through the valve byopening and closing the valve opening 440 in a graduated manner. In someexamples, the control valve 150 is in communication with the makeupcontroller 410.

In an example, the makeup controller 410 is in communication with thefluid level sensor array 120 and the makeup controller 410 isresponsible for determining the fluid level within the reservoir 115(shown in FIG. 1). In another example, the makeup controller 410 isconfigured to control the flow rate of the input fluid through thecontrol valve 150 by communicating with the control valve 150. In someexamples, the controlling of the flow rate is proportional to theturbulent fluid surface parameter determined by the makeup controller410. In some instances, graduating the introduction of the input fluidinto the reservoir 115 includes the makeup controller 410 automaticallycontrolling the valve opening 440 and corresponding flow rates throughthe valve opening 440 according to the established fluid level of theturbulated base fluid. In yet another example, the flow rate iscontrolled by the makeup controller 410 providing an input to thecontrol valve 150 that controls the valve opening 440 and regulates theflow rate through the control valve 150 (based on the established fluidlevel). In one example, the makeup controller 410 is a programmablelogic controller (“PLC”). In another example, the makeup controller 410includes a microprocessor.

In still yet another example, graduating the introduction of an inputfluid into the reservoir 115 (shown in FIG. 1) includes dynamicallyoperating the control valve 150 at full flow for a specified amount oftime, with the specified amount of time in proportion to the determinedbase fluid level. Stated another way, the introduction of the inputfluid into the reservoir 115, in this example, is graduated by operatingthe control valve 150 at a full flow rate for an amount of timecorresponding to a specified base fluid level of the base fluid. In anexample, if the discrepancy between the specified base fluid level andthe actual base fluid level is small, the control valve 150 is operatedfor a relatively small period of time. In another example, if thediscrepancy between the specified base fluid level and the actual basefluid level is relatively large compared to the previous smalldifference (e.g., because of increased steam needs) the control valve150 is operated for a longer time period to quickly achieve the fluidlevel to the specified base fluid level.

The precise and accurate determination of the fluid level allows forprecise and accurate controlled metering of the input fluid into thereservoir 115 (shown in FIG. 1). The precise metering of the fluidavoids large inputs of the input fluid at a single time and insteadallows a graduated input of the input fluid. The graduated input of theinput fluid facilitates the maintenance of evaporation/boil and allowsthe humidifier, boiler, etc. to maintain the specified output (e.g.,steam, vapor for humidification or the like).

FIG. 5 is a block diagram showing one example of a method 500 formaintaining a boiling rate of a base fluid. In some instances, themethod 500 includes the system 100, the fluid level sensor array 120,and/or the fluid level measuring apparatus 400. In describing the method500, reference is made to one or more components, features, functionsand steps previously described herein. Where convenient, reference ismade to the components, features, steps and the like with referencenumerals. The reference numerals provided are exemplary and are notexclusive. For instance, components, features, functions, steps and thelike described in the method 500 include, but are not limited to, thecorresponding numbered elements provided herein and other correspondingelements described herein (both numbered and unnumbered) as well astheir equivalents.

At 510, a fluid level of a turbulated base fluid in a reservoir isdetermined. In one example, at 520, the fluid level is determined bymeasuring at least one first height of the turbulated base fluid abovethe fluid level with at least a first sensor. In another example, at530, the fluid level is determined by measuring at least one secondheight of the turbulated base fluid below the fluid level with the firstsensor. In some instances, the measuring of the first height or thesecond height includes sensing the turbulated base fluid is above thefirst sensor. In an example, the measuring of the first height or thesecond height includes sensing the turbulated base fluid is below thefirst sensor. In yet another example, the measuring of the first heightor the second height includes establishing one or more of the firstheight or the second height according to the sensed turbulated basefluid above and below the first sensor.

In some examples, measuring the first height or the second height of theturbulated base fluid includes measuring a first time period theturbulated base fluid is above the first sensor during a sample period.In another example, measuring the first height or the second height ofthe turbulated base fluid includes measuring a second time period theturbulated base fluid is below the second sensor during the sampleperiod. In yet another example, measuring the first height or the secondheight of the turbulated base fluid includes establishing one or more ofthe first height or the second height according to the measured firstand second time periods. In some instances, establishing one or more ofthe first height or the second height according to the measured firstand second time periods includes establishing one or more of the firstheight or the second height according to a proportion of the measuredfirst time period to the second time period.

As described herein, in some instances, the first sensor is included ina sensor array. In a further example, measuring the first height and thesecond height of the turbulated base fluid includes sensing theturbulated base fluid is above the first sensor of a sensor array. Insome examples, measuring the first height and the second height of theturbulated base fluid includes sensing the turbulated base fluid isbetween the first sensor and a second sensor of the sensor array. Insome instances, measuring the first height and the second height of theturbulated base fluid includes sensing the turbulated base fluid isbelow the second sensor.

In an example, measuring the first height and second height of theturbulated base fluid includes measuring a first time period theturbulated base fluid is above the first sensor during a sample period.In another example, measuring the first height and second height of theturbulated base fluid includes measuring a second time period theturbulated base fluid is between the first and second sensors during thesample period. In yet another example, measuring the first height andsecond height of the turbulated base fluid includes measuring a thirdtime period the turbulated base fluid is below the second sensor duringthe sample period.

At 540, the method 500 includes establishing the fluid level of theturbulated base fluid according to the measured at least one first andsecond heights. In an example, establishing the fluid level includesestablishing the fluid level according to the sensed turbulated basefluid above, between and below the first and second sensors,respectively. In another example, establishing the fluid level includesestablishing the fluid level according to the measured first, second andthird time periods.

At 550, the method 500 includes graduating the introduction of an inputfluid into the reservoir with a control valve in proportion to theestablished fluid level of the turbulated base fluid. In some examples,the control valve includes a valve opening configured to regulate flowbetween flow rates including no flow, full flow and one or more flowrates therebetween. In one example, graduating the introduction of theinput fluid into the reservoir includes automatically controlling thevalve opening between the flow rates according to the established fluidlevel of the turbulated base fluid. In another example, graduating theintroduction of the input fluid into the reservoir includes dynamicallyoperating the control valve at full flow for a specified amount of time,with the specified amount of time in proportion to the determined fluidlevel.

Several options for the method 500 follow. In one example, the method500 includes repeating the establishing of the fluid level of theturbulated base fluid on an ongoing basis. In another example,graduating the introduction of the input fluid includes proportionallyopening the control valve according to the repeated establishing of thefluid level. In yet another example, the method 500 includes turbulatingthe base fluid. In an example, turbulating the base fluid includesbringing the base fluid to a boil. In another example, turbulating thebase fluid includes mechanically turbulating the base fluid.

VARIOUS NOTES & EXAMPLES

Aspect 1 may include or use subject matter (such as an apparatus, asystem, a device, a method, a means for performing acts, or a devicereadable medium including instructions that, when performed by thedevice, may cause the device to perform acts), such as may include oruse a method for maintaining a boiling rate of a base fluid. The methodmay include determining a fluid level of a turbulated base fluid in areservoir. The fluid level may be determined by measuring at least onefirst height of the turbulated base fluid above the fluid level with atleast a first sensor. The fluid level may be determined by measuring atleast one second height of the turbulated base fluid below the fluidlevel with the first sensor. The method may include establishing thefluid level of the turbulated base fluid according to the measured atleast one first and second heights. The method may include graduatingthe introduction of an input fluid into the reservoir with a controlvalve in proportion to the established fluid level of the turbulatedbase fluid.

Aspect 2 may include or use, or may optionally be combined with thesubject matter of Aspect 1, to optionally include or use that thecontrol valve may include a valve opening configured to regulate flowbetween flow rates including no flow, full flow and one or more flowrates therebetween. The method may include that graduating theintroduction of the input fluid into the reservoir includesautomatically controlling the valve opening between the flow ratesaccording to the established fluid level of the turbulated base fluid.

Aspect 3 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 1 or 2 to optionallyinclude or use that the control valve may include a valve openingconfigured to regulate flow between flow rates including no flow, fullflow and one or more moderate flow rates therebetween. The method mayinclude that graduating the introduction of the input fluid into thereservoir includes dynamically operating the control valve at full flowfor a specified amount of time, with the specified amount of time inproportion to the determined fluid level.

Aspect 4 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 1 through 3 tooptionally include or use that at least one of measuring the firstheight or the second height of the turbulated base fluid includes:sensing the turbulated base fluid is above the first sensor, sensing theturbulated base fluid is below the first sensor, and establishing one ormore of the first height or the second height according to the sensedturbulated base fluid above and below the first sensor.

Aspect 5 may include or use, or may optionally be combined with thesubject matter of Aspect 4 to optionally include or use that the methodmay include that measuring the first height or the second height of theturbulated base fluid includes: measuring a first time period theturbulated base fluid is above the first sensor during a sample period,measuring a second time period the turbulated base fluid is below thesecond sensor during the sample period, and establishing one or more ofthe first height or the second height according to the measured firstand second time periods.

Aspect 6 may include or use, or may optionally be combined with thesubject matter of Aspect 5 to optionally include or use that the methodmay include that establishing one or more of the first height or thesecond height according to the measured first and second time periodsincludes establishing one or more of the first height or the secondheight according to a proportion of the measured first time period tothe second time period.

Aspect 7 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 1 through 6 tooptionally include or use that the first sensor is included in a sensorarray. The method may include that measuring the first height and thesecond height of the turbulated base fluid includes: sensing theturbulated base fluid is above the first sensor of a sensor array,sensing the turbulated base fluid is between the first sensor and asecond sensor of the sensor array, and sensing the turbulated base fluidis below the second sensor.

Aspect 8 may include or use, or may optionally be combined with thesubject matter of Aspect 7 to optionally include or use that the methodmay include that establishing the fluid level includes establishing thefluid level according to the sensed turbulated base fluid above, betweenand below the first and second sensors, respectively.

Aspect 9 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 7 or 8 to optionallyinclude or use that the method may include that measuring the firstheight and second height of the turbulated base fluid includes:measuring a first time period the turbulated base fluid is above thefirst sensor during a sample period, measuring a second time period theturbulated base fluid is between the first and second sensors during thesample period, and measuring a third time period the turbulated basefluid is below the second sensor during the sample period.

Aspect 10 may include or use, or may optionally be combined with thesubject matter of Aspect 9 to optionally include or use that method mayinclude that establishing the fluid level includes establishing thefluid level according to the measured first, second and third timeperiods.

Aspect 11 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 1 through 10 tooptionally include or use that the method may include repeatingestablishing the fluid level of the turbulated base fluid on an ongoingbasis.

Aspect 12 may include or use, or may optionally be combined with thesubject matter of Aspect 11 to optionally include or use that the methodmay include that graduating the introduction of the input fluid includesproportionally opening the control valve according to the repeatedestablishing of the fluid level.

Aspect 13 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 1 through 12 tooptionally include or use that the method may include turbulating thebase fluid.

Aspect 14 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 13 through 13 tooptionally include or use that the method may include that turbulatingthe base fluid includes bringing the base fluid to a boil.

Aspect 15 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 13 through 14 tooptionally include or use that the method may include that turbulatingthe base fluid includes mechanically turbulating the base fluid.

Aspect 16 may include or use subject matter (such as an apparatus, asystem, a device, a method, a means for performing acts, or a devicereadable medium including instructions that, when performed by thedevice, may cause the device to perform acts), such as may include oruse a fluid level measuring apparatus. The apparatus may include a fluidlevel sensor array having one or more fluid level sensors, wherein theone or more fluid level sensors are configured to detect a turbulatedbase fluid at one or more heights in a reservoir. The apparatus mayinclude a makeup controller in communication with the fluid level sensorarray. The makeup controller may include a sampling module configured toreceive one or more heights of the turbulated base fluid from the fluidlevel sensor array. The makeup controller may include a fluid levelidentification module configured to determine a turbulated fluid surfaceparameter, based on the received one or more heights of the turbulatedbase fluid, the turbulated fluid surface parameter corresponding to thequantity of the base fluid contained in the reservoir.

Aspect 17 may include or use, or may optionally be combined with thesubject matter of Aspect 16, to optionally include or use that the oneor more fluid level sensors includes electrical characteristicinstruments.

Aspect 18 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 16 or 17 tooptionally include or use that the one or more fluid level sensorsincludes a float switch.

Aspect 19 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 16 through 18 tooptionally include or use a control valve having a valve opening. Thecontrol valve may be in communication with the makeup controller. Thevalve is configured to control a flow rate of an input fluid through thevalve. The makeup controller is configured to control the flow rateproportionally to the turbulated fluid surface parameter.

Aspect 20 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 16 through 19 tooptionally include or use that the reservoir is a water tank for ahumidifier.

Aspect 21 may include or use subject matter (such as an apparatus, asystem, a device, a method, a means for performing acts, or a devicereadable medium including instructions that, when performed by thedevice, may cause the device to perform acts), such as may include oruse a system for producing vapor. The system may include a reservoir forcontaining a turbulated base fluid. The system may include a fluid levelsensor array, coupled to the reservoir, and having one or more fluidlevel sensors, wherein the one or more fluid level sensors detect thepresence of the base fluid in the reservoir. The system may include amakeup controller in communication with the fluid level sensor array.The makeup controller may include a sampling module configured toreceive one or more heights of the turbulated base fluid from the fluidlevel sensor array. The makeup controller may include a fluid levelidentification module configured to determine a turbulated fluid surfaceparameter, based on the received one or more heights of the fluid level,the turbulated fluid surface parameter corresponding to the amount ofthe base fluid contained in the reservoir.

The system may include a control valve coupled to the reservoir for themetered introduction of an input fluid into the reservoir. The controlvalve may be in communication with the makeup controller. The controlvalve has a valve opening, wherein the valve opening is configured to beopened and closed. The control valve is configured to control a flowrate of an input fluid through the valve by gradually opening andclosing the valve opening. The makeup controller is configured tocontrol the flow rate of the input fluid through the control valve andthe controlling of the flow rate is proportional to the turbulated fluidsurface parameter.

Aspect 22 may include or use, or may optionally be combined with thesubject matter of Aspect 21, to optionally include or use that the oneor more fluid level sensors includes electrical characteristicinstruments.

Aspect 23 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 21 or 22 tooptionally include or use that the reservoir is a water tank for ahumidifier.

Aspect 24 may include or use, or may optionally be combined with thesubject matter of one or any combination of Aspects 21 through 23 tooptionally include or use that the base fluid is water.

Each of these non-limiting examples can stand on its own, or can becombined in various permutations or combinations with one or more of theother examples.

The above description includes references to the accompanying drawings,which form a part of the detailed description. The drawings show, by wayof illustration, specific embodiments in which the invention can bepracticed. These embodiments are also referred to herein as “examples.”Such examples can include elements in addition to those shown ordescribed. However, the present inventors also contemplate examples inwhich only those elements shown or described are provided. Moreover, thepresent inventors also contemplate examples using any combination orpermutation of those elements shown or described (or one or more aspectsthereof), either with respect to a particular example (or one or moreaspects thereof), or with respect to other examples (or one or moreaspects thereof) shown or described herein.

In the event of inconsistent usages between this document and anydocuments so incorporated by reference, the usage in this documentcontrols.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B.” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

Geometric terms, such as “parallel”, “perpendicular”. “round”, or“square”, are not intended to require absolute mathematical precision,unless the context indicates otherwise. Instead, such geometric termsallow for variations due to manufacturing or equivalent functions. Forexample, if an element is described as “round” or “generally round.” acomponent that is not precisely circular (e.g., one that is slightlyoblong or is a many-sided polygon) is still encompassed by thisdescription.

Method examples described herein can be machine or computer-implementedat least in part. Some examples can include a computer-readable mediumor machine-readable medium encoded with instructions operable toconfigure an electronic device to perform methods as described in theabove examples. An implementation of such methods can include code, suchas microcode, assembly language code, a higher-level language code, orthe like. Such code can include computer readable instructions forperforming various methods.

The code may form portions of computer program products. Further, in anexample, the code can be tangibly stored on one or more volatile,non-transitory, or non-volatile tangible computer-readable media, suchas during execution or at other times. Examples of these tangiblecomputer-readable media can include, but are not limited to, hard disks,removable magnetic disks, removable optical disks (e.g., compact disksand digital video disks), magnetic cassettes, memory cards or sticks,random access memories (RAMs), read only memories (ROMs), and the like.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

The claimed invention is:
 1. A method for maintaining a boiling rate of a base fluid, comprising: determining a fluid level of a turbulated base fluid in a reservoir, wherein the fluid level is determined by: measuring at least one first height of the turbulated base fluid above the fluid level with at least a first sensor, and measuring at least one second height of the turbulated base fluid below the fluid level with the first sensor; establishing the fluid level of the turbulated base fluid according to the measured at least one first and second heights; and graduating the introduction of an input fluid into the reservoir with a control valve in proportion to the established fluid level of the turbulated base fluid.
 2. The method of claim 1, wherein the control valve includes a valve opening configured to regulate flow between flow rates including no flow, full flow and one or more flow rates therebetween, and graduating the introduction of the input fluid into the reservoir includes automatically controlling the valve opening between the flow rates according to the established fluid level of the turbulated base fluid.
 3. The method of claim 1, wherein the control valve includes a valve opening configured to regulate flow between flow rates including no flow, full flow and one or more moderate flow rates therebetween, and graduating the introduction of the input fluid into the reservoir includes dynamically operating the control valve at full flow for a specified amount of time, with the specified amount of time in proportion to the determined fluid level.
 4. The method of claim 1, wherein at least one of measuring the first height or the second height of the turbulated base fluid includes: sensing the turbulated base fluid is above the first sensor, sensing the turbulated base fluid is below the first sensor, and establishing one or more of the first height or the second height according to the sensed turbulated base fluid above and below the first sensor.
 5. The method of claim 4, wherein measuring the first height or the second height of the turbulated base fluid includes: measuring a first time period the turbulated base fluid is above the first sensor during a sample period, measuring a second time period the turbulated base fluid is below the second sensor during the sample period, and establishing one or more of the first height or the second height according to the measured first and second time periods.
 6. The method of claim 5, wherein establishing one or more of the first height or the second height according to the measured first and second time periods includes establishing one or more of the first height or the second height according to a proportion of the measured first time period to the second time period.
 7. The method of claim 1, wherein the first sensor is included in a sensor array, and measuring the first height and the second height of the turbulated base fluid includes: sensing the turbulated base fluid is above the first sensor of a sensor array, sensing the turbulated base fluid is between the first sensor and a second sensor of the sensor array, and sensing the turbulated base fluid is below the second sensor.
 8. The method of claim 7, wherein establishing the fluid level includes establishing the fluid level according to the sensed turbulated base fluid above, between and below the first and second sensors, respectively.
 9. The method of claim 7, wherein measuring the first height and second height of the turbulated base fluid includes: measuring a first time period the turbulated base fluid is above the first sensor during a sample period, measuring a second time period the turbulated base fluid is between the first and second sensors during the sample period, and measuring a third time period the turbulated base fluid is below the second sensor during the sample period.
 10. The method of claim 9, wherein establishing the fluid level includes establishing the fluid level according to the measured first, second and third time periods.
 11. The method of claim 1, further comprising repeating establishing the fluid level of the turbulated base fluid on an ongoing basis.
 12. The method of claim 11, wherein graduating the introduction of the input fluid includes proportionally opening the control valve according to the repeated establishing of the fluid level.
 13. The method of claim 1, further comprising turbulating the base fluid.
 14. The method of claim 13, wherein turbulating the base fluid includes bringing the base fluid to a boil.
 15. The method of claim 13, wherein turbulating the base fluid includes mechanically turbulating the base fluid.
 16. A fluid level measuring apparatus comprising: a fluid level sensor array having one or more fluid level sensors, wherein the one or more fluid level sensors are configured to detect a turbulated base fluid at one or more heights in a reservoir; and a makeup controller in communication with the fluid level sensor array, wherein, the makeup controller includes: a sampling module configured to receive one or more heights of the turbulated base fluid from the fluid level sensor array, and a fluid level identification module configured to determine a turbulated fluid surface parameter, based on the received one or more heights of the turbulated base fluid, the turbulated fluid surface parameter corresponding to the quantity of the base fluid contained in the reservoir.
 17. The apparatus of claim 16, wherein the one or more fluid level sensors includes electrical characteristic instruments.
 18. The apparatus of claim 16, wherein the one or more fluid level sensors includes a float switch.
 19. The apparatus of claim 16, comprising a control valve having a valve opening, the control valve in communication with the makeup controller, wherein: the valve is configured to control a flow rate of an input fluid through the valve, and the makeup controller is configured to control the flow rate proportionally to the turbulated fluid surface parameter.
 20. The apparatus of claim 16, wherein the reservoir is a water tank for a humidifier.
 21. A system for producing vapor, comprising: a reservoir for containing a turbulated base fluid; a fluid level sensor array, coupled to the reservoir, and having one or more fluid level sensors, wherein the one or more fluid level sensors detect the presence of the base fluid in the reservoir; a makeup controller in communication with the fluid level sensor array, wherein, the makeup controller includes: a sampling module configured to receive one or more heights of the turbulated base fluid from the fluid level sensor array, and a fluid level identification module configured to determine a turbulated fluid surface parameter, based on the received one or more heights of the fluid level, the turbulated fluid surface parameter corresponding to the amount of the base fluid contained in the reservoir; and a control valve coupled to the reservoir for the metered introduction of an input fluid into the reservoir, wherein: the control valve is in communication with the makeup controller; the control valve has a valve opening, wherein the valve opening is configured to be opened and closed; the control valve is configured to control a flow rate of an input fluid through the valve by gradually opening and closing the valve opening, and the makeup controller is configured to control the flow rate of the input fluid through the control valve and the controlling of the flow rate is proportional to the turbulated fluid surface parameter.
 22. The apparatus of claim 21, wherein the one or more fluid level sensors includes electrical characteristic instruments.
 23. The apparatus of claim 21, wherein the reservoir is a water tank for a humidifier.
 24. The apparatus of claim 21, wherein the base fluid is water. 